[Sca-cooks] What does this Dripping Dish Do?

[Mercy Neumark]

So, I think by now you all know my first focus is pottery.  I do cook, but I make a lot of different items.  I go through the Museum of London site and try to find new items to make to sell and give sometimes as gifts to people.
 
I came across this: http://www.museumoflondon.org.uk/ceramics/pages/largerimage.asp?obj_id=113105%20&img_id=49153
 
Here is the description of the item: http://www.museumoflondon.org.uk/ceramics/pages/object.asp?obj_id=113105
 
So, I have my ideas as to what it does, but really... what does it do?  Is it for basting?  It has a spout/pouring lip.  It seems really long and cumbersome of anything else, but I could be wrong.  
 
Does anyone know of any good books that speak about what kitchen items did in period (how they were used)?  There are numerous warming dishes and oddities I can find, and honestly, I am not sure how someone would use these items.
 
Thanks!

--Mercy